(a) Field of the Invention
The present invention relates to contact structures of wirings and methods for manufacturing the same, and thin film transistor array panels including the same and methods for manufacturing the same.
(b) Description of the Related Art
Generally, wiring of semiconductor devices is to transmit signals without delay.
In order to prevent delay or distortion of signals, materials having a low resistivity such as aluminum or aluminum alloy are generally used. However, bad physical and chemical properties of the aluminum or aluminum alloy easily oxidizes and corrodes the aluminum or aluminum alloy, when connecting other conductive material in a contact portions, accordingly the characteristics of semiconductor devices are deteriorated. To improve contact properties of the wire made of aluminum and aluminum alloy, a different material is then inserted. However, to form the wire of multi-layered structure, several etchant to pattern the wire of multi-layered structure and several steps of the photolithography are needed. Accordingly, the manufacturing method is complicated, increasing production costs.
On the other hand, a liquid crystal display (LCD) is one of the most popular flat panel displays (FPDs). The liquid crystal display has two panels having electrodes for generating electric fields and a liquid crystal layer interposed therebetween. The transmittance of incident light is controlled by the intensity of the electric field applied to the liquid crystal layer.
In the most widely used liquid crystal display, the field-generating electrodes are provided at both panels, and one of the panels has switching elements such as thin film transistors.
In order to prevent delay or distortion of signals, materials having a low resistivity such as aluminum or aluminum alloy are also used in the liquid crystal display. However, when ITO (indium tin oxide) as a transparent electrode is used as a pixel electrode or to reinforce pad portions, the poor contact properties between aluminum or aluminum alloy and indium tin oxide (ITO) requires a different material to be inserted therebetween and the aluminum or aluminum alloy must be removed in the pad portions to prevent the corrosion of aluminum and aluminum alloy. Accordingly, the manufacturing method is complicated.
On the other hand, a thin film transistor array panel is manufactured by a photolithography process. Since the photolithography process is expensive, the number of the photolithography steps needs to be minimized.